Impeller wheel for torque converter or fluid coupling

ABSTRACT

The impeller wheel has a very desirable rigidity by reason of the fact that the shell of the impeller wheel is provided with an annular support member welded to its periphery, and that each blade of the impeller wheel is welded, at its rib, to the shell.

United States Patent 11 1 v 1111 3,873,237

Tokunaga 1 1 Mar. 25, 1975 [54] IMPELLEIR WHEEL FOR TORQUE 2,256,9889/1941 Michailoff 416/180 UX CONVERTER 01 FLUID COUPLING 2,347,0714/1944 Bailey 416/180 2,660,957 12/1953 Koskinen 29/1568 FC X Inventor:Masayoshi Tokunaga, Takatsukl, 2,799,228 7/1957 Farrell 416/180 Osala,.lapan 3,673,659 7/1972 lshii et a1. 29/1568 CF l g sl Neyagawa Osaka961,408 4/1957 Germany .1 416/221 p 802,837 10/1958 United Kingdom416/221 [22] F11ed: Dec. 17, 1973 [21] Appl. No: 425,297 PrimaryExaminerEverette A. Powell, Jr.

Attorney, Agent, or Firm-Pierce, Scheffler & Parker [30] ForeignApplication Priority Data 066. .111. 1972 16 m] 48-2817 ABSTRACT.

The impeller wheel has a very desirable rigidity by 1 1 416/180 reason01 the fact that the shell of the impeller wheel 1 1 f U B211 isprovided with an annular support member welded to 1 1 lleld 0 Search FCits periphery, and that each blade of the impeller wheel is welded, atits rib. to the shell. [56} References Cited UNITED STATES PATENTS 3Clams 5 Drawmg F'gures 2,061,997 11/1936 Dunn 416/180 I 11 m H 35 I fl/I I 1 l I 42 6 2.9. W I

PATEN YEW/H125 1975 SHEET 2 Of: 2

F" H G IMPELLER WHEEL FOR TORQUE CONVERTER OR FLUID COUPLING Thisinvention relates to an improved impeller wheel which can be used as animpeller in a turbine, in a torque converter or fluid coupling, orsimilar application.

The prior art impeller wheel, such as that disclosed in U.S. Pat. No.2,855,852, was of a type which comprised many stamped blades withpre-determined outer profiles, each blade being fixed between a shell(outer wall of working fluid) and a core ring (inner wall). In thisprior type of wheel, since each blade had a few tabs (or projections) onits inner and outer peripheries in one body, and the tabs were insertedand secured in the respective grooves or slits in the shell and corering, the

.holding rigidity of the blades was low. Therefore, the 7 higher thepressure of fluid around the blades, the more deformation, vibration andseparation of the blades occurred.

As is known, the pressure in the casing of a conventional torqueconverter or liquid coupling for a vehicle is 3 or 4 kg/cm or below, andit is also known that higher pressure minimizes the bad effect of air orgas contained in the liquid (oil) such as cavitation, which phenomenonmakes for poor performance of the device. Nevertheless, according to theabove-mentioned assembled type of impeller wheel, a pressure higher thanabove mentioned cannot be applied because of the low rigidity of thestructure. Especially, slits in the shell or core ring may easily causethe bursting of the torque converter. Also, the performance of the priorconstruction gradually deteriorates, because the place and angle of theconnection points between the blades and respective parts, and thecurvature of the blades, can easily change.

On the other hand, a stamped impeller shell needs, in general, at itsouter and or inner peripheries an annular support member, such as asupport ring, which is connected to a ring member secured on a rotaryhousing, or an impeller hub journalled in a stationary housing. Theannular support member functions to provide a liquid-tight connectionwith the ring member or stationary housing. In the case of torqueconverters for automobiles, the outer periphery of the impeller shell issometimes directly connected, by welding, to the rotary housing. Astamped shell for turbine wheel has a member (spline hub) to which theshell is secured by rivets. As mentioned above, in manufacturing eachimpeller wheel for a pump or turbine, a welding or rivetting process isrequired to attach an annular support member or members in addition tothe processes of fixing the blades onto the shell. The cost ofmanufacturing this prior type of impeller wheel was high in that muchlabor was required for assembling the parts.

The present invention avoids the above-mentioned disadvantages utilizingthe fact that each shell has at least an annular support member securedon its outer or inner periphery and the securing process can also beused at the same time to secure the blades onto the shell.

A principal object of the invention is to provide an impeller wheel of adesign favorable to a lower cost of manufacture. The impeller wheel hasa shell, many blades and a core ring, each blade having a rib at leastat its outer periphery in the same body, and each blade seating on theinner surface of the shell by means of the rib. Each blade is secured atthe rib to the shell by tabs provided on each end of the rib, bywelding, soldering or equivalent secure way, together with an annularsupport member, thereby increasing the rigidity and durability of theblades and of the wheel as a whole, and minimizing the labor forassembling the parts.

Another object of the invention is to provide an impeller wheel in whichthe distance between the blades does not change as time passes. and inwhich the profile of the blade also does not change, because each bladeis strengthened by the rib or ribs and preferably being stamped with therib or ribs in one piece from sheet metal, thereby giving highperformance of the impeller wheel.

A further inventive object is to provide an impeller wheel in which eachblade is accurately located in a shell and a core ring by means of bladeposition-setting means (tabs) provided on the rib, thereby simplifyingassembly of the blades with the shell and core ring.

Other objects of the invention will be apparent from the followingdescription, taken together with the accompanying drawing, in which:

FIG. 1 is a sectional view of an upper half part of a torque converteraccording to the present invention;

FIG. 2 is a partial view taken along line llll in FIG.

FIG. 3 is a perspective view of a blade used in FIG. 1; and

FIGS. 4 and 5 are partial sectional views of another impeller wheelembodying principles of the invention.

With reference to FIG. 1, the torque converter 10 comprises a drivingimpeller wheel 11, powered by an engine, which functions as a pump, adriven impeller wheel 12 which functions a turbine and a bladed stator13. The rotating pump wheel lltransmits energy to a working fluid whichlatter transmits energy to and drives turbine wheel 12 which is coupledto an output drive shaft 14.

The bladed stator 13 located intermediate the facing pump and turbinewheels 11, 12 remains stationary below a pre-determined output-inputspeed ratio of the turbine and pump impellers, to change the directionof the fluid to convert energy thereof.

Pump wheel 11 is connected to the flywheel 16 of an engine (not shown)by means including an annular drive plate 17 which is secured at itsouter peripheral portion to the face of the flywheel 16 by a ring ofcircumferentially spaced bolts 18. The inner peripheral portion of driveplate 17 is secured to a hub 19 by a similar ring of bolts 20, the hub19 including an axle 21 journalled in flywheel 16 by an anti-frictionbearing 22.

Hub 19 in turn is secured to a hub 23 by the same ring of bolts 20,which hub 23 is welded to the inner portion of rotary housing 24 as at25. Welded as at 26 on the outer periphery of rotary housing 24 is asupport ring 27. Around support ring 27 is asupport ring 28 which isfastened to support ring 27 by bolts 29 and a fluid tight seal isprovided therebetween by seal ring 30.

Impeller wheel 11 is composed of' the support ring 28, and a stampedshell 32, an impeller hub 33, a core ring 34 and a plurality of ribbedblades 35. Each ribbed blade 35 has ribs 36, 37 along its outer andinner peripheries. Rib 36 provides a snug fit with the interior surfaceof shell 32. Rib 37 fits on the core ring 34 in the same manner as rib36. Tabs 38, 39 formed at both ends of rib 36 are bent outwardly on theexterior surface of shell 32. Therefore, support ring 28 and shell 32abut each other having a plurality of tabs 38 interposed therebetween,and an annular clearance 40 (FIG. 2) which is equivalent with thethickness d of tab 38 is left between the tabs 38. Seam welding isapplied, as at 41, over the clearance 40 and tabs 38. Tabs 39 are alsoplaced between shell 32 and impeller hub 33, and are bent outwardly.Seam welding is also applied as at 42. Rib 36 may be secured on theinterior surface of shell 32 by way of spot welding, soldering or someother secure way if necessary.

Tabs 44, 45 formed at both ends of rib 37 are bent outwardly on theexterior surface of core ring 34 and soldered as at 46, 47. To sum up,the novel concept underlying the present invention is applied to theportions indicated circles A, B in the impeller wheel 11. Impeller hub33 is journalled in the stationary housing and a fluid-tight seal isprovided therebetween by seal ring 31.

The detailed structure of the turbine wheel 12 includes a shell 49, aspline hub 50, a core ring 51 and a plurality of ribbed blades 52. Thepresent invention is applied to the portion C in which tabs 53 formed atI the end of ribs 54 are located in the annular clearance formed betweenthe shell 49 and spline hub 50 abutting each other. The clearance andbent tabs 53 are filled and sealed by seam welding as at 55.

The spline hub 50 engages with a spline 57 on the previously mentionedoutput drive shaft 14 (i.e., a turbine shaft). Shaft 14 is journalled ona bearing 58 mounted inside hub 19 and support ring 23. A ring 59prevents the shaft 14 from slipping off axially.

Stator 13 preferably is cast in one piece, and is journalled on a fixedsleeve 61 through a oneway cluuth 62 which includes an outer race 63which engages with stator 13 through spline 64. Thus, as is well knownin the art, during the accelerating process of converting torque up to apredetermined output-input velocity ratio, stator 13 is fixed onstationary sleeve 61, whilst at a velocity above said velocity ratio,the stator is free to rotate in the same direction as that of drivenimpeller wheel or turbine 12, to make the converter act as a fluidcoupling.

In assembling the impeller wheel 11, first a plurality of ribbed bladesin the form of that shown in FIG. 3 are put on the interior annularsurface of shell 32 at regular intervals with an assemble jig (notshown) and tabs 38, 39 are bent outwardly as arrows shown in FIG. 3 andpressed on the exterior surface of shell 32. Then, support ring 28 andimpeller hub 33 are placed at the outer and inner peripheries of shell32 respectively in a pressed abutting relation with their end surfaces.Next, core ring 34 is placed on the array of ribs 37 and on its exterior(left side in FIG. 1) surface, tabs 44, are bent. Finally, seam weldingis applied as at 41, 42. Portions 46, 47 are soldered. Between shell 32and ribs 36, and between core ring 34 and ribs 37, spot welding,soldering or some other secure way may be applied.

In the prior art impeller wheel blades were fixed independently of (orapart from) the junction between the shell and support members such assupport ring (corresponding to support ring 380, impeller hub (33) andspline hub Therefore, much labor was required. Strong constructionagainst pressure was difficult to obtain.

But according to the present invention, for example, shell 32, tabs 38and support ring 28 are welded at the same time to make a unitaryconstruction. Therefore. the construction is not only easy tomanufacture but also is strongly resistant to pressure. In theconnection portions B, C, the same advantages are provided.

In FIG. 4, support ring 28 overlaps the array of tabs 38 which are bentand seated on the outer peripheries of the exterior surface of shell32'. Besides, tabs 38' are engaged in recesses (indents) 66 which arecircumferentially spaced at regular intervals and function asposition-setting means. Rightmost ends of tabs 38' are aligned with therightmost end surface of support ring 28' and welding is appliedannularly as at 41'. Thus three parts, i.e., tabs 38, support ring 28and shell 32'. are connected in one procedure of seam welding. Tostrengthen the construction, additional welding may be applied as at 67.

In the circle B in FIG. 4, about the same construction is employed.Impeller hub 33' has an annular recess 69 in which inner portion ofshell 32' is engaged interposing tabs 39' which are regularly spaced bymeans of indents 70 formed on the inner periphery of shell 32. Weldings42' and 71 are applied, if necessary.

According to the embodiment shown in FIG. 4, strength and rigidity ofthe construction increase, and accurate centering (or aligning of centerlines) between shell 32' and its support members such as support ring28' and impeller hub 33' is easy to set.

In the circle C in FIG. 4, indents 73 are formed on the inner peripheryof shell 40'. The indents 73 help blades 52 to dispose at regularintervals. It will be understood that the feature shown incircle C maybe applicable in conjunctions shown in circles A, B, C in FIG. 1.

In the embodiment of FIG. 5, rotary housing 24' laps on shell 32 andwelding is applied annularly as at 41 This unitary constructionadvantageously is employed in torque converters for automobiles.

I claim:

1. An impeller wheel for torque converter or fluid I coupling (11)comprising a shell (32); a core ring (34); a circular array ofcircumferentially spaced blades (35); and

a support ring member (28, 33) connected at at least one of the innerand outer peripheries of said shell (3 each of said blades having aleast a rib (36) with a configuration complementary to that of theinterior surface of said shell (32),

said rib (36) having a tab (38, 39) at at least one of t intervals onthe periphery of said shell (32').

l l l l l

1. An impeller wheel for torque converter or fluid coupling (11)comprising a shell (32); a core ring (34); a circular array ofcircumferentially spaced blades (35); and a support ring member (28, 33)connected at at least one of the inner and outer peripheries of saidshell (32), each of said blades having a least a rib (36) with aconfiguration complementary to that of the interior surface of saidshell (32), said rib (36) having a tab (38, 39) at at least one of theopposite ends of said rib (36), said shell (32) and support ring member(28) being welded annularly together with said tabs (38) interposedtherebetween.
 2. An impeller wheel for torque converter or fluidcoupling according to claim 1, in which said support ring member (28'')laps on the exterior periphery of the shell (32'').
 3. An impeller wheelfor torque converter or fluid coupling according to claim 1, in whicheach of said tabs (38'') engages in an indent (66) formed at regularintervals on the periphery of said shell (32'').